B2 says you will plan to use the most suitable runway based on forecast winds and considering landing aids and terrain. I'd read that to say if the runway that is into the wind is too short to meet the 60% but there is another longer runway there and you can stop in 60% of your alternate runway, you can go. Or if there is no approach to a longer runway but there is to a shorter one. There's an Op Spec for it that talks about crew experience and a bunch of other factors.